Building odd-shaped sub enclosure: MDF vs. Fiberglass

[Jtwheels2007]

I want to put a subwoofer into the side panel of the cargo area. Similar to stealth box, location, but where you ONLY see the sub the box is completely hidden behind panel. Bc of the wheel well shape, even the stealth box has to be odd shaped. Which method is easier to make, and how to i guarantee the proper airspace of such an odd shape?

[fastdel]

mdf evertime

[srtbull2004]

MDF certainly has it's purposes in the world of sub enclosures. I would say about 90% of boxes are built with MDF.
However, to get a perfect fit and finish in such a strange location, fibreglass is the way to go. You will maximize on air space, without taking up too much cargo area.

As far as getting the correct internal airspace, once the inside of the box is complete fibreglassed, I use measured water to figure out how much air space I have. It's a bit of a pain in the toosh, but it works like a charm.

[Dill]

I also would say fiberglass. The pain in the arse would be molding the panel.

[Jtwheels2007]

Originally Posted by srtbull2004

MDF certainly has it's purposes in the world of sub enclosures. I would say about 90% of boxes are built with MDF.
However, to get a perfect fit and finish in such a strange location, fibreglass is the way to go. You will maximize on air space, without taking up too much cargo area.

As far as getting the correct internal airspace, once the inside of the box is complete fibreglassed, I use measured water to figure out how much air space I have. It's a bit of a pain in the toosh, but it works like a charm.

Originally Posted by Dill

I also would say fiberglass. The pain in the arse would be molding the panel.

My concerns are this: with MDF, the THINEST u want to use is .5 inch. I do not know how thick the fiberglass has to be built up to to make it sturdy, But I imagine you can get away with alot less thickness. In additoion, the fiberglass can b molded around things like the wheel well no problem. that and I imagine fiberglassing the box TO the back of the panel would b alot easier than having some1 to drill or glue MDF to the back of it.


How do I make the fiberglass enclosure a certain air space, vs making a box and finding a sub to fit it. *considering I already have a sub in mind provided it meets the depth requirement". How COSTLY is fiberglass? I know it is a long involved process, but how expensive is all the materials?

[lowpt]

If you are considering attaching the fiberglass enclosure to a plastic panel, fiberglass doesn't bond well to plastic. There are a couple of ways to address this: drilling holes in the panel or gluing material to the plastic panel before applying resin. If you are considering doing this project my advice would to be to READ A LOT before actually starting it. As for figuring airspace you can resort back to math class and just break up the area you have to work with into smaller sections, figure the approx. space then add the measurements to get the total. After the enclosure is built you can fill it with packing peanuts then pour them into a cube shaped box and figure your displacement. Srt's water method is more accurate but the peanuts will get you close. GOOD LUCK!!

[PtOnAir]

I am going to be doing this real soon. Using an American bass xd6.5" woofer.

I would say you could easily get .5-.8 cubes from that area before displacement maybe even a tad more , Id have to see one with "grill" cut away to really be able to tell.Worse case you could cut the back out an gain even more space.

[Floundering]

Fiberglass is the only way to go for what you're considering. I would probably use an MDF face though. There's quite a few you tube videos on it if you want to see what's involved. My only added advice is to use only disposable materials (mixing bowls, latex gloves, cheap brushes, etc.) and find the thickest mat you can so you don't have to do that many layers. I found Tap plastics in my area carried a crazy amount of fiberglass material. I found some mat that was like 18 oz. so I only had to do 3 layers and it came to probably 3/8" which was probably overkill. My box doesn't flex at all.

[PtOnAir]

If , you are willing to cut the rear of the panel out to allow for more air space, I would suggest building as much as possible from MDF.If you want to make a mold of the "dip" I would suggest using several layers of 1.5 mat ( 6 - 8 layers should be enough ).You can lay multiple layers at once , "I" suggest to do no more than 4 layers at a time & let that cure , grind (if your resin contains wax, i do it either way) an add another 4 layers.

being a first timer I would suggest playing with a couple of batches to get your
"pot life" (time it takes for resin to start getting jelly/then hard) to where you like it.I would also suggest a good quality resin , as generally they're easier to work with compared to Bondo/Elmers brand resin.